I can’t remember how I found this, but you might want to check out TaskSwitchXP if you are interested in a highly-customizable Windows XP alt-tab replacement. I installed it today, and I think I’m gonna keep it loaded. It’s small and fast and generates a preview window of each application as you scroll through the list like this:

TaskSwitchXP is really fast… so fast it “feels” like the normal alt-tab utility — and not like the Microsoft PowerToy replacement which is really slow. TaskSwitchXP also has about 1 gillion things you can customize on it, is “distributed very free” and is open source… so what’s not to like?